Piano action



A. P. BROWN May 27, 1947.

PIANO ACTION Filed Dec. 13, 1945 INVENTOR. hfLEX/UVDER P BRONN BY MQJ% ArrbR/vEy Patented May 27, 1947 UNITED STATES PATENT OFFICE 5 Claims.

My invention relates to piano actions and, more particularly, to actions for miniature upright pianos or spinets of restricted dimensions.

Actions for pianos of this type have been provided with mechanisms connecting the key with an actuating element positioned at a lower level whereby the height of an action of otherwise more or less conventional structure is reduced, and such devices are known as underslung actions. They have several severe disadvantages. The mechanism interposed between the key and the proper action increases the number of parts required, requires higher expenses, makes the structure more complicated, makes the proper adjustment more difiicult and less reliable and results in a mushy touch and tones of poor quality.

Objects of my invention are to avoid these drawbacks; to provide for a position of the action which does not extend considerably over the level of the key; to actuate the proper action by direct blow or stroke of the key, and, thereby, to obtain tones of perfect quality.

Other objects are to provide a jack with a lower end positioned considerably below the level of the key; to provide a hammer with a pivoted butt positioned at its lower end; to provide for a hooking engagement between the jack and the hammer butt whereby the jack releasably engages the hammer and swings the same from the position of rest toward the sound string, can be disengaged from the hammer When the latter rebounds, and swings the hammer back from the rebounded position into the position of rest; to provide a wippen having an arm struck upward by the key and hingedly connected to the upper end of the jack whereby the latter is pulled up when the key is struck; and to provide a back check affixed to this wippen and positioned over the hammer.

Further objects are to provide a damper with a hinge positioned near its lower end and considerably below the level of the key, and to connect this damper with the jack by a bridal strip or tape whereby swinging movement of the jack to the front side withdraws the damper from the sound string, and the damper may be withdrawn by other means while the bridle strip slackens and does not move the jack.

Still other objects are to arrange the hammer and the jack at a short horizontal distance from each other; to facilitate, thereby, the hooked co-operatio-n of these parts; to provide, thereby, for a small horizontal measure of the action and of the piano; and to provide a structure of the hammer rest which can be positioned in the narrow space between the hammer and the jack.

Still further objects are to reduce the number of parts, to simplify the structure of a piano action of this type, and to make it unnecessary to provide the hammer with a spring.

Still other objects and advantages will appear from the following description of an exemplifying embodiment of my invention, from the appended claims and from the accompanying drawing in which the figure shows a vertical, partially sectional side view of this embodiment.

It should be noted that, throughout this specification and claims, the front side is understood to be the side facing the performer or the left side in the drawing, and the back side to be the side facing the sound string or the right side in the drawing.

Referring to the drawing, numeral 1 indicates a key of conventional structure shown broken ofi, the front part of this key being omitted. A capstan 2 is affixed to the key I near the back end of the latter, preferably by screwing the capstan 2 into the upper surface of the key. Thi capstan forms an adjustable contact.

The key I can be operated either by the hand of a performer or by a pneumatic action which may move a Wire 3 in vertical direction. The wire 3 may pass slidably through an opening of a block 4 affixed in any suitable manner, for example, by a screw 43 to the key frame 5 and may have an upper end provided with a head 6 contacting a felt layer 1 afixed to the lower surface of the key I. In both kinds of operation, the back end of the key I and the capstan 2 move upward when the key is struck.

A wippen 8 has a fixed pivot 9 positioned, in horizontal direction, beyond the key I. An arm ill of the wippen 8 is contacted from the lower side by the capstan 2 and has an end ll projecting upward. A screw l2 passes through a threaded opening of the wippen end I l and forms an adjustable jack trip. Another wippen arm I? extends from the pivot 9 in a direction about opposite to the arm iii and carries a back check l4 comprising a wire 15 which may be bent in order to adjust the position of the back check.

A jack I6 is hinged to the wippen 8 at a pivot point I! of the arm Ill. The pivot i7 is positioned between the fixed pivot 9 of. the wippen and the point of contact with the capstan 2. The upper end of the jack l6 projects over the arm Ii) sufficiently far to be contacted by the jack tri screw 12 during the last part of each key stroke. A spring is has a fixed end 19 and a movable end 28 contacting the upper end of the jack I S and urging the same about vertically downward, and counterclockwise with respect to the hinge IT.

The jack It extends from the pivot I! down in a slightly oblique direction, passes at the back side of the key I and has a lower end positioned considerably below the level of the key or of the key board. This lower end is provided with a projection 2i for releasable engagement with a hammer as will be described later.

The hammer has a shank 22 which, in the position of rest, is situated at a short distance from the jack H and at the back side thereof. A butt 23 having a fixed pivot 24 is ailixed to the lower end of the shank 22. A recess 25 is provided at the front side of the butt and is engaged by the projection 2i of the jack when the latter is not tripped out of this engagement by the pressure of the screw I2. Preferably, the pivot 24 is positioned at about the same low level as the projection 2i and the recess 25. The upper and the lower surface of the recess 25 may be padded with felt layers 44 and 45, and a thin layer 25 of suitable protective material, for example, buckskin, may be placed over these felt layers and adjoining parts of the butts surface.

A head 21 is affixed to the upper end or" the shank 2?. and is positioned below the wippen arm I3 and the back check I4 in the position of rest. The hammer can swing around the pivot 24 in clockwise direction until the head 21 hits the string 28 in the position shown in dotted lines. When the hammer rebounds from the latter position, a rounded surface 29 of the head 21 engages wedgingly a padded surface 30 of the back check which, at the same time, is positioned as shown in dotted lines.

A hammer rest 3i forms a stop for anti-clockwise movement of the hammer. In the position of rest, the shank 22 contacts a padded surface of the hammer rest 31. The latter is positioned in the narrow space between the shank 22 and the jack I 6, and suitable clearance is left between the rest 3i and the jack. In order make this arrangement possible, the structure of the hammer rest comprises, in contradistinction from the usual wooden bar or rail, a steel rail 32 which has a U-shaped cross-section having short legs bent into tight engagement with the pad of the rest 3|. This structure can be made suificiently strong without requiring much space in the direction perpendicular to the shank 22 and the jack IS.

A damper 33has a fixed pivot 34 and a head 35. A spring 35, having a fixed end 31 and a movable end 38 contacting the damper 33, urges the head into contact with the string 28. The damper 33 is connected to the jack I6 by a flexible element or a bridle strip 39 having a backend glued or affixed to the damper. At the front end, the bridle strip terminates in apiece of leather 4!) which is adjustably connected to the jack I 8. Preferably, a hook 4! made of wire and bendable for adjustment is affixed to the jack IS and has a free end engaging an opening of the piece 40.

The described piano action operates as follows:

When the key I is struck, the capstan 2 drives the wippen 8 in clockwise direction, raising the wippen arm I8 and lowering the back check I4. The raising arm It pulls the ja .1 upward whereby the projection 2I, engaging the recess 25 and pushing the upper surface thereof, turns the hammer around the pivot 24 into the position where the hammer head 21 strike the string 28 as shown in dotted lines.

The jack trip screw I2 is so adjusted that it contacts the upper end of the jack IS a short time before the key stroke is completed and that, when the hammer hits the string, the jack has been turned by the pressure of this screw, 3, little in clockwise direction around the hinge ll. Thereby, the projection 2| is withdrawn from the recess 25, and simultaneously, the bridle strip 39 and the damper 33 are drawn to the front side whereby the latter loses contact with the string. Then, the hammer, being disengaged from the projection 2| of the jack, rebounds and is caught by the back check I4 as described before.

When the key I is released, it returns into the shown position of rest. At the same time, the spring I 8 urges the jack I6 and the wippen 8 back into the shown position, the jack trip screw !2 losing contact with the jack, and the projection 2| entering again the recess 25 and pushing the lower surface thereof down whereby the hammer is returned into the position shown in full lines.

I desire it understood that my invention is not confined to the particular embodiment shown and described, the same being merely illustrative, and that my invention may be carried out in other ways without departing from the spirit of my invention as it is obvious that the particular embodiment shown and described is only one of the many that may be employed to attain the objects of my invention.

Having described the nature of my invention, what I claim and desire to protect by Letters Patent is:

1. In a piano action, a combination comprising a key having a back end moving up when the key is struck, a wippen having a fixed pivot positioned, in horizontal direction, beyond said key end, and having two arms, one of said arms having a lower side drivingly contacted by said key end, a back check afiixed to the other arm, a jack hinged to said first wippen arm whereby said jack moves up when said key is struck, said jack extending down across the back side of said key and having a projection positioned considerably lower than said key, and a hammer having a butt and afixed pivot in said butt, said butt having a recess engageablc by said projection, said hammer having a head located, in the position of rest, below said other wippen arm and engaging said back check in rebounded position.

2. In a piano action, a combination comprising a key having a back end moving up when the key is struck, a wippen having a fixed pivot positioned, in horizontal direction beyond said key end, and having two arms, one of said arms having a lower side drivingly contacted by said key end, a back check aifixed to the other arm, a jack hinged to said first wippen arm whereby said jack moves up when said key is struck, said jack extending down across the back side of said key and having a projection positioned considerably lower than said key, a hammer having a butt and a fixed pivot in said butt, said butt having a head located, in the position of rest, below said other wippen arm and engaging said back check in rebounded position, a spring urging said jack down and its projection into engagement with said recess, and a jack trip screw adjustably aiilxed to said wippen and so positioned that, at the end of a stroke, said trip screw urges said jack in a direction where said projection is disengaged from said recess.

3. In a piano action, a combination comprising a key having a back end moving up when the key is struck, a wippen having a fixed pivot positioned, in horizontal direction, beyond said key end, and having two arms, one of said arms having a lower side drivingly contacted by said key end, a back check affixed to the other arm, a jack hinged to said first wippen arm whereby said jack moves up when said key is struck, said jack extending down across the back side of said key and having a projection positioned considerably lower than said key, a hammer having a butt and a fixed pivot in said butt, said butt having a recess engageable by said projection, said hammer havi a head located, in the position of rest, below said other wippen arm and engaging said back check in rebounded position, a damper having a fixed pivot positioned considerably lower than said key, and a bridle strip having one end connected to said damper and having another end connected to said jack,

4. In a piano action, a combination comprising a key having a back end moving up when the key is struck, a wippen having a fixed pivot positioned, in horizontal direction beyond said key end, and having two arms, one of said arms having a lower side drivingly contacted by said key end, a back check afiixed to the other arm, a jack hinged to said first wippen arm whereby said jack moves up when said key is struck, said jack extending down across the back side of said key and having a projection positioned considerably lower than said key, a hammer having a butt and a fixed pivot in said butt, said butt having a recess engageable by said projection, said hammer having a head located, in the position of rest, below said other wippen arm and engaging said back check in rebounded position, an adjustably bendable wire affixed to said jack, a damper having a fixed pivot positioned considerably lower than said key, and a bridle strip having one end connected to said wire and having another end connected to said damper.

5. In a piano action, a combination comprising a key having a back end moving up when the key is struck, a wippen having a fixed pivot positioned, in horizontal direction, beyond said key end, and having two arms, one of said arms having a lower side drivingly contacted by said key end, a back check affixed to the other arm, a jack hinged to said first wippen arm whereby said jack moves up when said key is struck, said jack extending down across the back side of said key and having a, projection positioned considerably lower than said key, a hammer having a shank positioned at a short distance from said jack and at the back side of the same, a head affixed to the upper end of said shank and positioned below said other wippen arm in the position of rest and engaging said back check in rebounded position, butt affixed to the lower end of said shank, having a fixed pivot and having a recess engageable by said projection, and a back rest positioned between said jack and said hammer shank and comprising a steel rail of U-shaped cross-section.

ALEXANDER P. BROWN. 

